COMPENSATION COURT.

Evening Star, Issue 12769, 23 March 1906, Page 3

COMPENSATION COURT.

THE MOMONA CLAIMS. (Before J. F. Woodhouse, Esq., Arbitrator.) r ‘ ho following transpired after we went to press yesterday : Mr Stephens • Supposing the wail of the dam. is Ift thick and the water flowing an inch over, and also supposing the same condition with a wall of 20ft thick, what is the difference between the effects on the \clocity of the water? . .Mr Beal: Shall I take the length of the dam measured across the stream as 66ft? Mr Stephens: I'es. Witness proceeded to make his mathematical calculations, but had not completed ihern at the luncheon hour. On the Court resuming id the afternoon Mr Beal was asked by Mr Woodhouse if !ie bad completed bis calculations. Witness said he would require more time •o do so. Mr Woodhouse; How much more time »ill you require ’' W it ness : If I had certain works on hydraulics, that would aid me, though I should have to be sure that they were applicable to this case. Mr Stephens : We have some works here. Will they do? Mr MacGregor: They are not enough. It was eventually decided to allow witness until the next sitting to make the required calculation, and his further crosscxaminaiion by Mr Stephens then proceeded, A question of that kind was outside his ordinary experience. A calculation implying an outlet of 20ft wide at dead level was an unusual one. The fact of it being at dead level caused so much calculation and hunting-np. If it was a by-wash there would be a fall away from it, and it would not have any crest- of any width. These outfalls usually discharged over a narrow sill that was an inch or two with a drop, but when it came to 20ft dead level the fnotion and soakago affected the question. Dealing with an inch of water, the friction on the inch would be increased towards the outer or discharging edge. The effect of the friction and the velocity would he that there would be less depth at the point of discharge than there would be at the point of entrance. He could not state the proportion. The effect of that particular class of outlet was that the friction got less at the point of discharge —that was, assuming tno width was 20ft thick. He was so satiswith his experience that he did not consider it necessary for him to make calculations on this subject. The greater the depth of water, the greater the velocity—that could be accepted as an axiom. The swfes of the dam proper would only slightlv restrict the quantity of the water which weald flow over the dam. They would cause a little friction at the edges of discharge. The effect of the friction would be that there would bo a little Lees water to escape. Very little contraction would be caused to the volume of water going over. He had observed a velocity of to theset end in the cross-cut. He did not gauge the depth at the time. On another occasion he found the depth of water in the erups-cut to be . 18in, He could not say what was the state of the tide. He noticed ou ’ 26th February that the velocity (< f water in the cross-cut was greater than it was on the previous occasion. He thought the depth on, that day would be about 3ft 3iii. Be. did not take anv measurements ; hfe coodfisaoQS were based on ordinary oh-

seryaticns. He did not think that the velocity in Dnck Creek at the cross-cut would be more than 3in a second under flood conditions. The, water would be practically stagnant. The velocity of the water was an item lie had consistently observed in his ordinary visits about the district, and the result of his observations was that he believed the velocity at .low tide was only slightly increased. He did not care to have any opinions respecting hydraulic questions. The tidal effect on the flow of water in Duck Creek had a very important bearing on the question of the flooding of Momona. At this point the Court adjourned until 10.30 on Monday next.